wiki:sqlite3:sqlite3_get_table
DISQLite3: sqlite3_get_table() example
DISQLite3 implements a self-contained, embeddable, zero-configuration SQL database engine for Delphi (Embarcadero / CodeGear / Borland).
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{ DISQLite3 example showing the use of sqlite3_get_table(). CAUTION: sqlite3_get_table() is a concenience function only. If the query returns lots of data, sqlite3_get_table() will consume huge amounts of memory! Developers are advised to stay far, far away from sqlite3_get_table() and use sqlite3_prepare(), sqlite3_step(), and sqlite3_finalize() instead. This demo is not meant to encourage the use of sqlite3_get_table(). It was written to answer a support question which explicitly asked for an example. Visit the DISQLite3 Internet site for latest information and updates: https://www.yunqa.de/delphi/ Copyright (c) 2005-2017 Ralf Junker, The Delphi Inspiration <delphi@yunqa.de> ------------------------------------------------------------------------------ } program DISQLite3_sqlite3_get_table; {$APPTYPE CONSOLE} {$I DI.inc} {$I DISQLite3.inc} uses SysUtils, DISQLite3Api; const DB_FILENAME = 'test.db3'; var DB: sqlite3; e: PAnsiChar; r, c: Integer; Table_Data: PPAnsiCharArray; Table_Row_Count, Table_Column_Count: Integer; begin try try { Create a new database with simple test table and data. } DeleteFile(DB_FILENAME); sqlite3_open(DB_FILENAME, @DB); sqlite3_exec_fast(DB, 'CREATE TEMP TABLE test (a, b, c)'); sqlite3_exec_fast(DB, 'INSERT INTO test VALUES (1,2,3)'); sqlite3_exec_fast(DB, 'INSERT INTO test VALUES (4,5,6)'); sqlite3_exec_fast(DB, 'INSERT INTO test VALUES (7,8,9)'); { Run a query using sqlite3_get_table. } if sqlite3_get_table( DB, // The databae handle. 'SELECT * FROM test', // SQL query to execute. Pointer(@Table_Data), // Write data result to array of PAnsiChar here. @Table_Row_Count, // Write number of result rows here. @Table_Column_Count, // Write number of result columns here. @e) // Write error message here on failure. = SQLITE_OK then begin { Query successful? Write result to console. } { Columnn Names are first. } Write('|'); for c := 0 to Table_Column_Count - 1 do begin Write(Table_Data[c], '|'); end; WriteLn; { Write horizontal line as data separator. } Write('-'); for c := 0 to Table_Column_Count - 1 do begin Write('--'); end; WriteLn; { Row data follows next. } for r := 1 to Table_Row_Count do begin Write('|'); for c := 0 to Table_Column_Count - 1 do begin Write(Table_Data[r * Table_Column_Count + c], '|'); end; WriteLn; end; { Free allocated table data. } sqlite3_free_table(Table_Data); end else begin { Failure? Output error message. } WriteLn(e); sqlite3_free(e); end; sqlite3_check(sqlite3_close(DB), DB); except on e: Exception do WriteLn(e.Message); end; finally WriteLn; WriteLn('Done - Press ENTER to Exit'); ReadLn; end; end.
wiki/sqlite3/sqlite3_get_table.txt · Last modified: 2020/08/28 11:43 by 127.0.0.1